code: def testEmpty(self):
      expected = []
      self.assertEqualVector(SpectralWhitening()([], [], []), expected)
  
file_path: essentia/test/src/unittests/spectral/test_spectralwhitening.py
imports: from essentia_test import *
label_desc: Use image node_id 2 for calling the TestSpectralWhitening obj's underlying member method code with example usage: obj.testEmpty() without return types